If it has been in sal****er(you used the word "canna" so I would guess
Scotland) the long bolt in the leading edge may need a lot of heat to shift
the corrosion. A good propane torch usually works. This engine is also prone
to drive shaft locking in the crankshaft at the bottom of the powerhead. If
that has happened it's goodbye. Just drop it off the transom in the Clyde.